Effect of water and salinity stress on germination and seedling characters in onion

The purpose of this study was to investigate the effect of water and salt stress on seed germination (germination per cent, mean germination time, germination synchrony and germination uncertainty) and seedling characters (seedling length, seedling fresh and dry weight and seedling vigor) in onion. Four water stress levels induced by PEG-6000 (0, -0.2, -0.4 and-0.6 MPa) and six salt stress levels of NaCl (0, 50, 100, 150, 200 and 250 mM) were studied and results revealed that increasing level of stress caused a gradual and significant decrease in germination and seedling growth. Water stress reduced germination by 22 to 83% and it was delayed by 2.19 to 4.69 days and salt stress also showed similar trend and prolonged the germination time by 0.46 to 4.68 days and reduced the germination by 3 to 57%.